ScanGauge temp data

This site may earn a commission from merchant affiliate
links, including eBay, Amazon, Skimlinks, and others.


Oct 9, 2006
Dayton, OH
I realize every engine coolant temp will vary some, but I thought I would post this question to get an idea of temp ranges.

At idle what coolant temps are you seeing?

For me I see between 190-195 when I am stopped in traffic or at a light. Ambient temps are between 50-80 degrees depending on time of day.

For comparison, driving temps range from 188-193 in similar ambient temps.

this looks perfectly normal
My '97 w/ a fairly new OEM radiator and blue hub clutch w/ 10K cst fluid usually reads 177-181 while driving and when stopped at a light it rarely goes past 184.

My wife's '96 w/ original rad and blue hub clutch w/ 10K cst fluid runs 179-182 driving down the road and runs 184-188 at idle.
When driving, 99% of the time it is between 179 and 181 (original radiator flushed, new foam around radiator, modified blue hub).

If I remember to look when stopped in traffic at idle, I'll edit this post with those values.
Thanks for the responses guys.

I am gearing up for a coolant system overhall and thought I would post up some pre-work numbers. The truck was flushed and refilled last Feb. 09 with Toyota red, new hoses, thermostat, and blue-hib fan clutch. Coolant temps are fairly consistant, but have gone up a degree or two in the last year. Mostly due to the original radiator (97') and the heavy scaling I noticed in it when I flushed it last year. I imagine with the install of the new OEM brass radiator (w/foam) and fresh coolant the numbers may come down a bit.

Keep those numbers coming for those who have the SG.
Last edited:
Replaced radiator with older OEM version, new blue hub fan clutch stock, new thermostat, and used Toyota Red with distilled water. Since then, about a year ago, normal driving around town temps are 182-186. On freeway, 184-188, going up Donner Summit hits 190, but I have OD off. I do have 315s and 5.29s.

the OEM thermostat opening temperature is 176-183F per FSM, call it 180 on average. It should be "fully" opened at 203F. In other words some the temps mentioned above are at the very low end of this range. And one would expect them to be higher. Seems like either those thermostats open "early" or the cooling system is "overdimensioned" (maybe cuz of mods or low ambient temps) or the sensor / gauge is off.
Last edited:
e9999...I appreciate the explination. Thanks!
I see 190-193 at idle and highway travel, whether on the trail or in traffic. I have seen 205 going up larger hills here while pulling the trailer but they quickly drop back to 190-193 once I am back on flat ground.

Stock cooling system, just flushes, etc. Have thought about a new BH fan clutch and thermostat but haven't seen the need yet, I don't guess?? Seems I am running a little higher than some folks.....

Mine was between 190-195 (even 204 on a mile long uphill) before my coolant flush last year. I also replaced rad hoses and the thermostat and I am now getting 180-186. :) (Though, I have not seen the 90 degree summer temperature yet.)
I completely rebuilt my cooling system a little over 2 years ago and the most recent flush was Aug 09.

Freeway driving temps are between 186-190

Traffic stop light temps 190-193 with occasional 195 after driving up a long hill and stopping.

211,000 miles on the truck.
Stock cooling system, flushed. Haven't changed out the fan clutch (or modded it) nor the radiator, but they're fairly clean.

184-190* in regular driving conditions, in stop-and-go traffic 188-193*.

As stated previously, this could change once the temps outside climb above the occasional 65-70* experienced today.

Users who are viewing this thread

Top Bottom